CN213574301U

CN213574301U - Silencer for exhaust system

Info

Publication number: CN213574301U
Application number: CN202022365664.1U
Authority: CN
Inventors: 钟灵贵; 黄兴来; 曾志新; 张凯; 吴丹; 黄元章
Original assignee: Guangzhou Automobile Group Co Ltd
Current assignee: Guangzhou Automobile Group Co Ltd
Priority date: 2020-10-21
Filing date: 2020-10-21
Publication date: 2021-06-29
Anticipated expiration: 2030-10-21

Abstract

The utility model belongs to the technical field of making an uproar falls in the automobile exhaust, a silencer for exhaust system is disclosed, it includes shell, end cover and perforated pipe, the shell with the end cover is connected and is formed an inclosed barrel, the both ends opening of perforated pipe and cross-under respectively are in the both ends terminal surface of barrel, the equipartition has the perforation of a plurality of intercommunication barrel cavitys on the pipe wall of perforated pipe, the perforation is equipped with crooked hole neck. Because the friction damping of the hole neck can attenuate sound waves, when the incident sound waves are consistent with the natural frequency of gas in a closed cavity formed by the perforated pipe, the end cover and the shell, the vibration generated by the gas column of the hole neck overcomes the friction force in the vibration process, thereby consuming sound energy and achieving the noise reduction effect.

Description

Silencer for exhaust system

Technical Field

The utility model belongs to the technical field of make an uproar falls in the automobile exhaust, especially relate to a silencer for exhaust system.

Background

With the stricter regulations of the national regulations on the automobile emission, the NVH problem is more and more critical for customers. The novel noise reduction structure aims to solve the emission problem caused by the traditional sound absorption cotton noise reduction structure, and simultaneously reduces noise and improves the NVH performance of exhaust. The frequency band of making an uproar falls in the needs through testing exhaust noise, adopts the novel structure of making an uproar of falling of numerical analysis to arrange the optimal position, combines the exhaust temperature of optimal position to microperforated equivalent aperture, perforation rate, board thickness and cavity thickness on the perforated pipe are design parameter, and seek the optimization algorithm through the particle swarm, solve the optimal novel parameter that the structure of making an uproar relates of falling, adopt the optimal parameter to carry out product design production.

The traditional high-frequency broadband silencer needs to additionally increase the acoustic resistance (adopting the filling sound absorption cotton) to reach the acoustic resistance equivalent to that of tail gas because of the large perforation rate of the hole pipe of the silencer, and a better sound elimination effect can be obtained. In the filling process of the sound absorption cotton, plastic bags are required for packaging. When the exhaust system is in operation, the plastic bag can be degraded by combustion with the rise of temperature, and harmful emission substances are generated. Meanwhile, as the operation time of the exhaust system is prolonged, the sound absorption cotton (made of glass fiber) has the risk of breakage at high temperature, and the broken glass fiber is easily discharged into the atmosphere along with gas and enters the lung along with the breathing of a person, so that the health problem is generated.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a simple structure, with low costs need not to adopt the sound absorption cotton also can reach the silencer for exhaust system of same noise reduction effect.

In order to achieve the above object, the utility model provides a silencer for exhaust system, it includes shell, end cover and perforated pipe, the shell with the end cover is connected and is formed an inclosed barrel, perforated pipe's both ends opening and cross-under respectively are in the both ends terminal surface of barrel, the equipartition has the perforation of a plurality of intercommunication barrel cavitys on perforated pipe's the pipe wall, it is equipped with crooked hole neck to perforate.

As the preferred scheme of the utility model, the equivalent diameter of perforation is less than 1 mm.

As a preferable embodiment of the present invention, the bending angle of the hole neck is 90 degrees.

As the preferred scheme of the utility model, the central axis of perforation pipe with the central axis of barrel is coaxial.

As the preferred scheme of the utility model, the shape in fenestrate outer end drill way is isosceles trapezoid.

As the preferred scheme of the utility model, the thickness of shell is 0.6mm-1mm, the thickness of end cover is 0.6mm-1 mm.

As the preferred scheme of the utility model, the tip of perforation pipe with the terminal surface welding of barrel.

As the preferred scheme of the utility model, be equipped with on the end cover with the tip complex interface of perforated pipe, the interface with the tip welding of perforated pipe.

As the preferred scheme of the utility model, the outer fringe of end cover is equipped with the arch and bordures, the arch bordure with the tip interlock of shell.

Implement the utility model provides a pair of a silencer for exhaust system compares with prior art, and its beneficial effect lies in:

when the system exhausts, high-speed gas enters the perforated pipe, sound waves are transmitted by taking tail gas as a carrier, the sound waves can enter the cavity of the cylinder body through the perforations on the perforated pipe, but the sound waves can be attenuated due to frictional damping of the hole neck, when the incident sound waves are consistent with the natural frequency of the gas of the closed cavity formed by the perforated pipe, the end cover and the shell, the vibration generated by the gas column of the hole neck overcomes the frictional force in the vibration process, so that the sound energy is consumed, the noise reduction effect is achieved, meanwhile, the sound absorption cotton arrangement of the traditional silencer can be cancelled, the product weight reduction is facilitated, and the discharge of harmful substances is reduced.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.

Fig. 1 is a schematic structural diagram of a muffler for an exhaust system according to the present invention;

FIG. 2 is a schematic structural view of a perforated pipe;

FIG. 3 is a cross-sectional view taken along line A-A in the configuration shown in FIG. 2;

fig. 4 is a partial enlarged view of the region B in the structure shown in fig. 2.

The labels in the figure are:

1 is a shell, 2 is an end cover, 21 is a raised edge, 22 is a connector, and 3 is a perforated pipe; 4 is a cylinder body, 5 is a perforation, and 6 is a hole neck.

Detailed Description

The following detailed description of the embodiments of the present invention is provided with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used merely for convenience of description and simplification of description, and do not indicate or imply that the machine or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention. It should be understood that the terms "first", "second", etc. are used herein to describe various information, but the information should not be limited to these terms, and these terms are only used to distinguish one type of information from another. For example, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information, without departing from the scope of the present invention.

As shown in fig. 1 and 2, the utility model discloses a silencer for exhaust system of preferred embodiment, it includes shell 1, end cover 2 and perforated pipe 3, shell 1 with end cover 2 connects and forms an inclosed barrel 4, perforated pipe 3's both ends opening and respectively the cross-under be in the both ends terminal surface of barrel 4, the equipartition has the perforation 5 of a plurality of intercommunication barrel cavitys on perforated pipe 3's the pipe wall, perforation 5 is equipped with crooked hole neck 6.

When the system exhausts, high-speed gas enters the perforated pipe 3, sound waves are transmitted by taking tail gas as a carrier, the sound waves can enter the cavity of the cylinder body through the perforations 5 on the perforated pipe 3, but the sound waves can be attenuated due to frictional damping of the hole neck 6, when the incident sound waves are consistent with the natural gas frequency of a closed cavity formed by the perforated pipe 3, the end cover 2 and the shell 1, vibration generated by a gas column of the hole neck 6 overcomes frictional force in the vibration process, so that sound energy is consumed, the noise reduction effect is achieved, meanwhile, the sound absorption cotton of a traditional silencer can be omitted, the product weight reduction is facilitated, and the discharge of harmful substances is reduced.

It was experimentally verified that the acoustic volume of the perforated pipe 3 is related to the perforation 5 rate, while the acoustic resistance is inversely proportional to the aperture. Therefore, the equivalent aperture of the perforation 5 of the perforated pipe 3 is controlled to a certain specific value below 1mm, the relative acoustic impedance of the sound absorption structure is equivalent to the specific relative acoustic impedance of the tail gas, the maximum sound absorption coefficient (the maximum noise reduction capability) can be obtained at the moment, a broadband noise reduction structure is formed, and the sound absorption cotton of the traditional silencer is cancelled.

It should be noted that, the filling density of the sound absorption cotton of the traditional sound absorption high-frequency broadband muffler is estimated to be 0.12kg/L, the price of the sound absorption cotton in the market is 50 yuan/kg at present, the plastic packaging bags are 0.5 yuan/piece, the filling volume of the common design is estimated to be 3L, and the sound absorption cotton can be cancelled by adopting the muffler structure of the embodiment, so that a single set of muffler product can generate 18.5 yuan of economic benefit, and simultaneously, the muffler structure is beneficial to reducing the discharge of harmful emission substances and protecting the environment.

Illustratively, as shown in fig. 1, the perforated pipe 3 is a pipe body that is rolled out to form perforations 5 using a stainless steel plate and then welded by rolling to form openings at both ends. The shell 1 is formed by rolling and snapping a stainless steel plate and is of a cylindrical structure with two open ends. The end cover 2 is formed by stamping a stainless steel plate, a raised edge 21 is formed on the outer edge of the end cover 2, and the raised edge 21 is in snap joint with the end part of the shell 1; the middle part of the end cover 2 is provided with a connector 22 matched with the end part of the perforated pipe 3, and the connector 22 is welded with the end part of the perforated pipe 3. Therefore, the design structure is simple, the manufacturing is easy, and the cost is low.

For example, as shown in fig. 3, the bending angle of the throat 6 is 90 degrees, which is beneficial to increasing the depth of the hole and effectively increasing the sound absorption coefficient.

Illustratively, as shown in fig. 1, the central axis of the perforated pipe 3 is coaxial with the central axis of the cylinder 4, so as to ensure the uniformity of the thickness of the cavity.

Illustratively, as shown in fig. 4, the shape of the outer end orifice of the through hole 5 is isosceles trapezoid, which is beneficial to the hole equivalent diameter and the processing.

Illustratively, in order to ensure the strength and the sound insulation effect of the external shell of the silencer, the thickness of the shell 1 is 0.6mm-1mm, and preferably 0.8 mm; the thickness of the end cap 2 is 0.6mm to 1mm, preferably 0.8 mm.

It should be noted that, as shown in fig. 3 and 4, the design of the respective parameters of the perforated pipe 3, such as: the widths d1 (upper side) and d2 (lower side) of the outer end orifices of the through holes 5, the thickness T1 of the through holes 5 (namely the distance from the upper side to the lower side of the outer end orifices of the through holes 5), the number n of the through holes 5, the thickness T2 of the through holes 3 and the thickness T of the closed cavity are obtained by testing exhaust noise, analyzing the frequency band central frequency and bandwidth needing noise reduction, building a mathematical model and solving by adopting a particle swarm optimization algorithm.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and replacements can be made without departing from the technical principle of the present invention, and these modifications and replacements should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a silencer for exhaust system which characterized in that, includes shell, end cover and perforated pipe, the shell with the end cover is connected and is formed an inclosed barrel, the both ends opening of perforated pipe just cross-under respectively the both ends terminal surface of barrel, the equipartition has the perforation of a plurality of intercommunication barrel cavitys on the pipe wall of perforated pipe, the perforation is equipped with crooked hole neck.

2. A muffler for an exhaust system according to claim 1, wherein the equivalent diameter of the perforations is less than 1 mm.

3. The muffler for an exhaust system of claim 1, wherein the bending angle of the throat is 90 degrees.

4. The muffler for an exhaust system according to claim 1, wherein a central axis of the perforated pipe is coaxial with a central axis of the cylinder.

5. The muffler for an exhaust system of claim 1, wherein the perforated outer end orifice is shaped as an isosceles trapezoid.

6. The muffler for an exhaust system of claim 1, wherein the shell has a thickness of 0.6mm to 1mm and the end cap has a thickness of 0.6mm to 1 mm.

7. The muffler for an exhaust system according to claim 1, wherein an end of the perforated pipe is welded to an end surface of the cylinder.

8. The muffler for an exhaust system according to claim 7, wherein the end cap is provided with an interface that mates with the end of the perforated pipe, the interface being welded to the end of the perforated pipe.

9. The muffler for an exhaust system of claim 1, wherein the outer edge of the end cap is provided with a raised lip that snaps into engagement with the end of the outer shell.